Aerodynamic design considerations for small-scale, fixed-pitch, horizontal-axis wind turbines operating in class 2 winds.
Access changed 1/13/14.
Renewable sources of energy, such as wind, are necessary to meet the growing demand as conventional energy sources are depleted. Very little research has been accomplished to improve wind turbine performance in Class 2 winds. This work experimentally analyzed techniques to improve the aerodynamic performance of small-scale, fixed-pitch, horizontal-axis wind turbines in Class 2 winds. Experimental data for the S823 airfoil was taken for Reynolds numbers from 50,000 to 200,000. A trip strip was shown to improve airfoil performance for Reynolds numbers below 100,000. Additional wind tunnel studies validated the wind turbine testing procedure. Using blade element theory (BET) and blade element momentum theory (BEMT), wind turbine blades with optimum angle of twist were designed and tested. Results suggest the BEMT-optimized blades will perform better at the design point. The sensitivity of the design angle on power production was also examined, resulting in negligible difference for the conditions tested.